Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece
and leave with the element ID LEGO asks for, or a link to buy the part.
832 pieces in 296 part and color combinations, plus 3 minifigures.
The official piece count includes the 12 parts inside the set's minifigures, which this inventory lists separately. Spare parts are counted in neither figure.
Before you call it missing
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
Look-alike colors in this set
These parts appear in this set in two colors that are easy to confuse. If you are one short in one color,
check whether it went in where the other color belongs. Each color has its own element ID in the parts list
at the back of the instructions.
Plate Round 1 x 1 with Solid StudYellow ×1Trans-Yellow ×1Trans-Yellow is see-through: hold the piece up to a light.
Tile 1 x 2 with GrooveBlack ×2Dark Blue ×1Black is yellower and darker than Dark Blue.
Technic Gear 12 Tooth BevelTanPart 6589Element 4565452 or 4514556×2
Wheels and Tyres
2 pieces
Wheel Bicycle, Fixed Black TireTrans-ClearPart 92851Element 6503209 or 6163986×2
Minidoll Upper Body
1 piece
Minidoll Torso Girl with White/Magenta/Black Shapes Shirt Print, Light Nougat Arms and HandsLight NougatPart 92456c01pr0409Element 6351937×1
Minifigs
1 piece
Minifig Trophy StatuetteWhitePart 90398Element 6551374 or 62994921 spare in the box×1
Rock
1 piece
Rock 1 1/3 x 1 1/3 x 1Dark OrangePart 35646Element 6382738×1
Stickers
1 piece
Sticker Sheet for Set 41711-1[No Color/Any Color]Part 10001507Element 6387459×1
Technic Steering, Suspension and Engine
1 piece
Technic Engine CrankshaftLight Bluish GrayPart 2853Element 6640384 or 4211609×1
Tools
1 piece
Brick and Axle Separator v2.0OrangePart 96874Element 6240515 or 4654448×1
Minifigures
3 figures
Emma - White Top, Medium Azure SkirtMinifigure, checked as a whole figure×1
Prof. BéatriceMinifigure, checked as a whole figure×1
FelixMinifigure, checked as a whole figure×1
Tick each piece as you find it, or mark it missing.
When a piece really is missing
Ask LEGO
LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for
the set number and each piece's element ID, the number printed beside the piece in the parts list at the back
of the instructions. This checker lists both.
Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from
older or second-hand sets.
Keep a record
Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick
pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.